AD-mix
Encyclopedia
AD-mix in organic chemistry
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...

 is a commercially available mixture of reagent
Reagent
A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...

s for performing amongst others the Sharpless asymmetric dihydroxylation
Sharpless asymmetric dihydroxylation
Sharpless asymmetric dihydroxylation is the chemical reaction of an alkene with osmium tetroxide in the presence of a chiral quinine ligand to form a vicinal diol....

 of alkenes. The mix is available in two variations, "AD-mix α" and "AD-mix β" following ingredient lists published by Sharpless. As such it is used in research laboratories.

The mixes contain:
  • Potassium osmate K2OsO2(OH)4 as the source of Osmium tetroxide
  • Potassium ferricyanide
    Potassium ferricyanide
    Potassium ferricyanide is the chemical compound with the formula K3[Fe6]. This bright red salt contains the octahedrally coordinated [Fe6]3− ion. It is soluble in water and its solution shows some green-yellow fluorescence.-Preparation:...

     K3Fe(CN)6, which is the re-oxidant in the catalytic cycle
    Catalytic cycle
    A catalytic cycle in chemistry is a term for a multistep reaction mechanism that involves a catalyst . The catalytic cycle is the main method for describing the role of catalysts in biochemistry, organometallic chemistry, materials science, etc. Often such cycles show the conversion of a...

  • Potassium carbonate
    Potassium carbonate
    Potassium carbonate is a white salt, soluble in water , which forms a strongly alkaline solution. It can be made as the product of potassium hydroxide's absorbent reaction with carbon dioxide. It is deliquescent, often appearing a damp or wet solid...

  • Chiral ligands (see below)


In AD-mix α (DHQ)2PHAL (top) is the phthalazine adduct with dihydroquinine
Dihydroquinine
Dihydroquinine, also known as hydroquinine, is an organic compound and as a cinchona alkaloid closely related to quinine. The specific rotation is -148° in ethanol. A derivative of this molecule is used as chiral ligand in the AD-mix for Sharpless dihydroxylation....

.



In AD-mix β; (DHQD)2PHAL is the phthalazine adduct with dihydroquinidine
Dihydroquinidine
Dihydroquinidine is an organic compound and as a cinchona alkaloid closely related to quinine. The specific rotation is +226° in ethanol @ 2g/100 ml. A derivative of this molecule is used as chiral ligand in the AD-mix for Sharpless Dihydroxylation....

.

External links

  • Catalytic Asymmetric Dihydroxylation of Alkenes at Imperial College London Link
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